Clinical and morphologic findings are described in 17 patients who died suddenly and unexpectedly during or shortly following use of the liquid-protein-modified-fast diet. Of the 17 patients, 16 were women, most were young (average age equals 37 years), and most lost a massive amount of weight (average equals 41 kg or 35% of their pre-diet weight) over a short period of time (average equals 5 months). Eight had one or more episodes of syncope. Multiple-lead electrocardiograms were recorded in 10 patients; all had normal sinus rhythm; all had episodes of ventricular tachycardia; nine and possibly 10 patients had prolongation of the Q-T interval unassociated with the recognized causes of Q-T interval prolongation in at least seven of the nine patients; and nine had diminished amplitude of the QRS complexes ("low voltage").